Cadmium Adsorption from Aqueous Solutions by Mine Tailings : Batch Experimental Studies

Heavy metals are considered as one of the important pollutants in the environment, particularly in the aquatic ecosystems. The presence of cadmium in food chain is toxic to human health. Different physical or chemical methods have been used for removing heavy metal ions in the water and wastewater treatments. The aim of this work was to assess the possibility of Cd removal from aqueous solutions by mine tailings, consisting mainly shale stones, from Irankouh lead and zinc mine, situated in Isfahan province, Iran. The adsorption experiments were carried out using batch technique, and the effects of pH, initial metal concentration and contact time on adsorption efficiency were studied. The results indicated that Cd adsorption increases with pH from 2 to 7 and maximum adsorption (%63) obtained at pH 6 and initial concentration of 10 mg/l. It is demonstrated that the mine tailings could be used as a low cost and effective adsorbent for cadmium.